A team from the International Atomic Energy Agency (IAEA) is due to meet Iranian officials in Tehran to discuss Iran's controversial nuclear program.
The IAEA team is expected on December 13 to press Iranian officials on access to information, officials, and locations the UN-affiliated agency thinks may have played a role in any work on a suspected nuclear weapons program.
Herman Nackaerts, who heads the IAEA's nuclear investigation, said his team was "ready to go" to one suspected site, Parchin, just as soon as Tehran approved the visit.
"Our aim for this trip is to reach agreement on a structured approach to resolve the outstanding issues related to possible military dimensions to Iran's nuclear program," Nackaerts said.
"This structured approach has been on negotiations now for almost one year. We also hope that Iran will allow us to go to the site of Parchin, and if Iran granted us access we would welcome that chance and we are ready to go."
The IAEA suspects Iran has done explosives tests with possible nuclear applications at Parchin, a facility southeast of the Iranian capital.
The IAEA also says satellite images indicate Iran is cleaning up the site to wipe away any trace of suspicious activity carried out there.
Iran rejects Western charges it is secretly developing nuclear weapons and says its nuclear program is for power and medical research.
Iranian President Mahmud Ahmadinejad was quoted on December 12 as saying he had already announced in 2007 that Iran had "become nuclear" by mastering all aspects of peaceful atomic technology.
Ahmadinejad said cooperation was the only way to resolve any outstanding issues on his country's nuclear program, but said some Iranian officials oppose this.
Commentators say Ahmadinejad has been sidelined on the Islamic republic's nuclear program, with hard-liners criticizing the Iranian president for saying Iran is ready for dialogue with the United States on its nuclear program.
Meanwhile, Helga Schmid, deputy director of the European's Union's diplomatic corps, has spoken by phone with Ali Bagheri, Iran's deputy nuclear negotiator.
Speaking to Reuters, an EU official said the two discussed possible dates and venues for a fresh round of talks between Iran and six world powers.
Three rounds of talks this year -- involving Britain, France, Germany, the United States, Russia, and China -- produced no breakthrough.
With reporting by dpa, Reuters, and AP